S3527 Pancreatic Fistulas Involving the Portal Vein and Pleural Space: Two Case Reports on Complex Presentations and Management

Introduction: A rare yet serious complication of pancreatitis is fistula formation. Pancreatic fistula (PF) develops as the integrity of the pancreatic ductal system gets disrupted by parenchymal inflammation, causing leakage of pancreatic secretions into nearby tissues. The clinical presentation varies depending on the anatomical destination of the fistula, often appearing atypically and making diagnosis and management difficult. Case Description/Methods: Case 1: A 59-year-old man patient with chronic idiopathic pancreatitis developed a pancreatic–pleural fistula (PPF), presenting as a massive, recurrent right-sided pleural effusion. Thoracentesis revealed an elevated pleural fluid lipase level, and the diagnosis was confirmed by imaging and endoscopic retrograde cholangiopancreatography (ERCP) demonstrating a pancreatic duct leak into the pleural space via a sinus tract extending from the pancreas to the mediastinum. The patient underwent thoracic surgical intervention together with multiple chest tube placements and endoscopic stenting. Case 2: A 52-year-old man with a history of chronic alcoholic pancreatitis presented with worsening abdominal pain. Imaging revealed extensive portal vein thrombosis, and despite anticoagulant therapy, thrombosis continued to worsen. Further evaluation revealed a rare pancreatic–portal vein fistula (PPVF). The diagnosis became evident through imaging and intraoperative portal system contrast injection, which opacified a pancreatic pseudocyst, confirming pancreaticoportal communication. The patient needed multiple endoscopic stent placements, cystogastrostomy, and an extended course of anticoagulant therapy. Discussion: PPVF and PPF are rare, diagnostically challenging, and therapeutically complex complications of pancreatitis. In both cases, fistula-related symptoms preceded radiologic evidence of the fistula, contributing to delays in diagnosis and definitive treatment. This diagnostic lag, coupled with the severity of associated complications, such as portal vein thrombosis and recurrent pleural effusion, leads to substantial morbidity and mortality risk in PF cases. In patients with a long-standing history of pancreatitis who present atypically, pancreatic fistula should be considered in the differential diagnosis. Early recognition allows a prompt and specific treatment approach, which decreases patient complications and enhances their clinical outcomes.